Mechanical time fuse



Aug. 26, 1947.

C. C. FAWCETT.

MECHANICAL TIME FUSE Filed Dec. 15, 1939 Patented Aug. 26, 1947 UNHTED'STATES FATENT ZAZMW (Granted under the act of March 3, 1883, as amendedApril 30, 1928; 3'70 0. G. 757) 2 Claims.

The invention described herein may be manufactured and used by or forthe Government for governmental purposes, without the payment to me ofany royalty thereon.

This invention relates to a firing pin actuated fuse and moreparticularly to a safety barrier for preventing ignition of the fuseprimer upon premature or accidental release of the firing pin.

While the invention has particular reference to a barrier for a firingpin, it is not limited to this sole function; but may also be of utilityin bstructing or blocking any passage in any suitable fuse where it isdesired to block such passage until a predetermined time in order torender the fuse safe.

It is an object of this invention to provide a positive acting firingpin barrier automatically inoperative upon firing a projectile armedwith a fuse provided therewith and which is simple in construction,economical in manufacture and so arranged as to lend itself to compactadaptation in the fuse organization.

The specific nature of the invention as well as other objects andadvantages thereof will clearly appear from a description of a preferredembodiment as shown in the accompanying drawings in which:

Fig. 1 is a horizontal sectional view through a fuse provided with afiring pin barrier embodying the invention;

Fig. 2 is a sectional view taken on the line 22 of Fig. 1;

Fig. 3 is a plan View on an enlarged scale of a lever used in the firingpin barrier; and,

Fig. 4 is an end elevation of the structure shown in Fig. 3.

Referring. now to the drawings wherein like characters are used toindicate lik parts throughout the views there is shown in Fig. l asupporting plate or similar frame member I!) comprising one of aplurality of similar superimposed members constituting the framework forsupporting and housing the fuse components.

The plate I0 is eccentrically recessed as indicated at ll within whichis disposed the safety barrier of this invention generally indicated at12. Radially outward of the plate It and within the recess II the plateis formed. with a passage !3 through which the firing pin l4 may projectto impinge upon and ignite the primer P5 in operative communication withan explosive train of the fuse.

The safety barrier 12 comprises a pair of identical cranked safetylevers l6 mounted at the point of intersection of their arms I? and 18on a pivot pin I9, whose center is located on the radial line of memberIll passing through the center of passage l3, in such manner that thearms ll will normally lie in registering relation covering passage l3while the arms I 8 will be disposed in diverging relation to form thescissors-like arrangement shown. To restrain the levers iii to theirnormal position as shown in Fig. 1, a stop pin 20 is disposed betweenthe arms 5 8 of the levers on the radial line passing through thecenters of pin is and passage l3 and resilient elements 2!, which may bein the form of flat springs suitably anchored at one end are so disposedas to have their free ends engage and urge the arms it of the levers [6into abutting relation with the stop pin 20. Conveniently in theembodiment of the invention illustrated th stop pin 28 is located at thecenter of member III.

For a purpose hereinafter made clear the free ends of the arms it of thelevers it are provided with centrifugal weights 22. While these Weightsare shown confronting each other in Fig. 1 it will of course beunderstood that in forming the levers the weights are all appliedthereon in the same manner to facilitat production.

In operation the levers It will occupy a normal position as shown inFig. 1 in which position the arm ll of each lever will cover the passagel3 in such manner as to prevent the firing pin M from striking theprimer l5.

If the fuse bearing this barrier receive a shock from the right side asviewed in Fig. 1 the rightmost lever it will pivot about its pivot pinl9 against the cooperating spring 2! but the lever 16 on the left willbe restrained from moving by the stop pin 20 and thereby continue toblock the passage is whereby the firing pin M will be unable to strikethe primer l5 in the event that the shock also released the firing pin.The reverse action will take place if the fuse receives a shock from itsleft side so in any situation the two levers 46 arranged as hereindisclosed will be effective to maintain the fuse safe untilpredetermined operation is desired.

When a fuse provided with the barrier of this invention is used to arm aprojectile the rotation imparted to the projectile in firing will besufficient through the centrifugal force developed to cause bothweighted arms 18 to swing about their pivot l9 and in turn swing thearms I! to uncover passage is. After the lapse of a predetermined timethe firing pin Ill will be released and is then free to impinge upon andignite the primer [5.

Having now particularly described what is at present considered apreferred embodiment of this invention I claim and desire to secure byU. S. Letters Patent:

1. In a fuse in combination, a supporting member formed with a passagetherethrough, a pair of, superimposed cranked levers coaxially pivotedon the supporting member intermediate their end portions with two of thearms of said levers normally disposed in registering relation blockinsaid passage and the other two arms of said levers arranged in divergingrelation, a stop pin disposed'between said diverging arms and resilientmeans urging the diverging arms into abutting relation with the stop pinto maintain S id arms blocking the passage in normal registeringrelation.

2. In a fuse in combination, a circular supporting member eccentricallyrecessed on one face and formed with a passage therethrough in therecess on a radial line, a pivot pin mounted on the member within therecess and on said radial line, a pair of superimposed identical crankedlevers mounted on the pivot pin intermediate their end portions andadapted to have two arms brought into registering relation covering saidpassage and the other two arms diverging from said pivot pin, weights onthe end portions of the diverging arms of the levers, a stop pin mountedon the member within the recess on said radial line intermediate thediverging arms of the levers and adapted to be abutted by the divergingarms when the other arms of the levers are in registering relationcovering said passage and resilient means normally urging the divergingarms into abutment with said stop pin.

CECIL o. FAWoET'r.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,172,637 Semple Feb. 22, 1916FOREIGN PATENTS Number Country Date 467,392 Great Britain June 16, 1937635,441 France Mar. '15, 1928

